• Proceedings of the KWS Conference
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• v.43
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• pp.222-224
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• 2004

• Digital Contents
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• no.12 s.67
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• pp.98-105
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• 1998

눈에 보이지 않지만 하루에도 수없이 많은 사이트가 만들어지고 또 쓰러지는 적자생존의 장 인터넷. 승자들의 사이트는 과연 무엇이 다를까? 패자의 사이트에는 어떤 문제가 있을까? 성공한 사이트와 실패한 사이트의 벤치마킹을 통해 인터넷비즈니스의 영원한 승자가 되는 길을 알아본다.

• Proceedings of the KSEE Conference
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• 2007.03a
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• pp.127-134
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• 2007

• Proceedings of the Korean Nuclear Society Conference
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• 2001.10a
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• pp.74.2-74
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• 2001

• 한국상하수도협회지
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• s.6
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• pp.130-147
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• 2004

• Proceedings of the Korean Nuclear Society Conference
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• 2002.10a
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• pp.71.2-71
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• 2002

• Digital Contents
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• no.10 s.65
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• pp.78-83
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• 1998

브라우저 전쟁으로 대표되던 인터넷 시장이 최근에는 포틀사이트 시장으로 그 각축전이 치열하다. 빅 사이트들의 움직임과 마케팅의 귀재 섹스 사이트들의 비결 그리고 성공 사이트들의 마케팅 노하우 벤치마킹을 통해 성공 인터넷 비즈니스의 지름길을 살펴봤다.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.1
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• pp.202-208
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• 2014

Friction force on robot systems is highly nonlinear and especially disturbs precise control of the robots at low speed. This paper deals with the dynamic friction compensation problem of a well-known one-link benchmark robot system. We consider the LuGre model because the model can successfully represent dynamic characteristics and various effects of friction phenomenon. The proposed controller is constructed as two parts. An adaptive controller based on dual observers is used to estimate and compensate the dynamic friction. In order to attenuate the friction estimation error and other disturbances, PI observer is additionally designed. Through the computer simulations with the benchmark system, this paper first examines the effects of nonlinear dynamic friction on the control performance of the benchmark robot system. Next, it is shown that the control performance against the dynamic friction is improved by using the proposed controller.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.3
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• pp.97-105
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• 2007

This study was conducted to compare the performances of acidogenic fermentation and hydrogen fermentation using bench-scale leaching-bed reactors for organic solid waste. Acidogenic fermenters were operated with dilution rates (D) of 2.0, 3.0 and $4.0d^{-1}$ after employing anaerobic sludge and hydrogen fermenters were operated with D of 2.0, 4.0 and $6.0d^{-1}$ after employing heat-treated anaerobic sludge. The highest chemical oxygen demand (COD) conversion efficiency (56.2%) was obtained in acidogenic fermentation with D of $3.0d^{-1}$. Only volatile fatty acid (VFA) was produced as a metabolite. On the other hand, hydrogen fermentation did not show higher COD conversion efficiency (49.3%) than acidogenic fermentation, but it produced hydrogen gas (5.1% of total COD) which was a clean and environmentally friendly fuel with a high energy yield. Therefore, either acidogenic fermentation or hydrogen fermentation could be applied to organic solid waste depending on the purpose of treatment, which could maximize the economics of anaerobic treatment.

• Journal of KIISE:Software and Applications
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• v.37 no.9
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• pp.694-705
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• 2010

The mutation operation is the main operation in the evolutionary programming which has been widely used for the optimization of real valued function. In general, the mutation operation utilizes both a probability distribution and its parameter to change values of variables, and the parameter itself is subject to its own mutation operation which requires other parameters. However, since the optimal values of the parameters entirely depend on a given problem, it is rather hard to find an optimal combination of values of parameters when there are many parameters in a problem. To solve this shortcoming at least partly, if not entirely, in this paper, we propose a new mutation operation in which the parameter for the variable mutation is theoretically estimated from the self-adaptive perspective. Since the proposed algorithm estimates the scale parameter of the Cauchy probability distribution for the mutation operation, it has an advantage in that it does not require another mutation operation for the scale parameter. The proposed algorithm was tested against the benchmarking problems. It turned out that, although the relative superiority of the proposed algorithm from the optimal value perspective depended on benchmarking problems, the proposed algorithm outperformed for all benchmarking problems from the perspective of the computational time.